Key-seat reamer



Sept. l5, 19.59 2,904,313

L. D. V. WISENBAKER KEY-SEAT REAMER Filed March l2, 1957 2,904,313 Patented Sept. 15, 1959 United StatesA Patent Oliice 2,904,3*13 KEY-SEAT REAMER Lorenzer D. V. Wisenbaker, Houston, Tex. i Application March 12, 1957, Serial No. 645,606

' z claims. (c1. zss-73) This invention relates to a key-seat reamer and more particularly to a reamer which is adapted to be connected into a string of drill pipe for use in Well drilling operations and by the use of which a key-seat formed in a well bore may be enlarged to preventv sticking the drill pipe in such a seat.

In the drilling of wells, such as oil and gas Wells, keyseats or slots are often formed in the well bore due to rotation of the drill pipe in contact with the wall of the bore at a curved portion of the bore. The drill pipe is of somewhat smaller external diameter than the external diameter of the drill bit, so that the rotation of the drill pipe in contact with the wall of the bore at a curved portion of the bore results inthe formation of a longitudinal slot or key-seat which is of smaller diameter than that of the bore, and in withdrawing the drill pipe from a well bore in which such a key-seat is present there is danger that the drill collars may enter and become wedged in the key-seat.-

The present invention has for an important object the provision of a reamer lwhich is adapted to be connected into a string of drill pipe and which is rotatable with the string to ream away the formation and enlarge the well bore at a key seat. p

Another object of the invention is to provide a keyseat reamer adapted to be connected into a drill string and whichv is shaped to permit circulation of drilling uid in the bore past the reamers during the drilling operation.

A further object of the invention is the provision of a key-seat reamer embodying a tubular body and having external, yspiraled cutting elements extending longitudinally of the body in circumferentially spaced relation.

Another object of the invention is to provide a key-seat reamer of the kind referred to which is shaped to be easily disengaged from a key-seat in a well bore by longitudinal movement of the drill string in the event that the reamer should become wedged in such a key-seat.

A further object of the invention is the provision of a key-seat reamer having a tubular body of substantially uniform external diameter throughout its length and provided with elongated external, circumferentially spaced cutter elements formed with cutting edges which taper from a point mediate the ends of the elements toward their opposite ends.

Another object of the invention is to provide a key-seat reamer having a tubular body of substantially uniform diameter throughout its length and provided with elongated, longitudinally tapering, spiraled, external cutter elements formed with leading edge portions which extend radially beyond the weld deposit and with trailing surface portions which are joined to the external surface of the body by deposited weld material.

The above and other important objects and advantages of the invention may best be understood from the following detailed description constituting a specification of the same when considered in conjunction with the annexed drawings, wherein- Figure 1 is a side elevational view of the invention,

on a reduced scale, showing the invention connected into a drill pipe in a well bore and illustrating the manner in which the invention is used;

Figure 2 is a side elevational view of the invention, showing the same detached from the drill string and illustrating details of construction of the reamer;

Figure 3 is a bottom plan View of the invention as seen in Figure 2; and

Figure 4 is a cross-sectional view, on a somewhat enlarged scale, taken along the line 4-4 of Figure 2, looking in the direction indicated by the arrows.

Referring now to the drawings in greater detail, the reamer of the invention is illustrated in Figure l, connected into a drilling string of conventional construction, designated S, positioned in the bore W of a well, such as an oil well, having a key-seat K therein, such as might be formed by rotation of the drill string in contact with the wall of the *bore at a curved portion of the bore.

In well equipment of this type the drill pipe is of substantially smaller external diameter than the bore W of the well, while the drilling bit, not shown, attached to the lower end of the string has an external diameter which is the same as that of the bore. Above the drilling bit, one or more drill collars, also not shown, are connected into the string whose external diameter is usually somewhat smaller than that of the bit but substantially larger than the external diameter of the drill pipe. In the presence of a key-seat in the well bore, such seat has a diameter equal to the external diameter of the drill pipe but smaller than that of the drill collars which have a tendency to enter the seat during Withdrawal of the string from the bore and to become wedged therein.

It is for the purpose of overcoming the above difficulty encountered in the presence of key-seat formationsin well bores that the present invention is provided, the keyseat reamer comprising a tubular body 10, of substantially uniform external diameter throughout its length, having an externally threaded pin 12 at one end and an internally threaded box 14 at the other end by which the body may be connected into the drill pipe S. The body 10 has an external diameter substantially equalto that of the drill pipe, and is provided with external, elongated, spiraled cutter elements 16 welded to the external surface of the body in circumferentially spaced relation.

Each of the cutter elements 16 is preferably of rectangular shape in cross-section, having one face positioned in tangential relation to the external surface of the body and secured thereto by means of weld deposits, indicated at 18 and 20 along the longitudinally extending sides of the elements, and which deposits may extend somewhat inwardlyv beneath the elements to securely bond the elements to the body.

The elements may conveniently be applied to the body by welding one end of each element to the body and fitting the element in `a spiral to the body by hammering or clamping the element in the desired spiraled position and welding the same along its opposite sides to the body, to form externally opening, spiraled, grooves or channels 22, spaced circumferentially about the body and open at their opposite ends.

When the cutter elements have been so applied to the body, the body is preferably supported in a lathe for rotation about its longitudinal axis and the other faces of the elements are cut or ground down to form curved outer surfaces 24 which taper from a location of maximum diameter mediate the ends of the elements toward locations of minimum diameter at the opposite ends of the elements, as best seen in Figure 2.

The leading or cutting edge portions of the cutter elements project radially beyond the weld deposits 18 and are provided with built up deposits 26 of hardened cut- .3 ting .material or otherwise treated to form -hardened cutting edges.

The weld deposits 20, along the trailing faces of the cutter elements, .preferably extend entirely across :the trailing faces, 'as .best -seen Figure 14 .to securely i bond' the elements to the body andtoform a substantial backing 11einforcing :for Vthe, elementssto strengthen vthe Same.

After the cutter elements have ibeenweldediinzplace on the body and cut or'ground to shape and the hard-material 26 deposited on the leading edge portions .fthe vdeposited materialfis 1ground.down to :shaperthecutting edgeszto conform to `the longitudinal taperaofftheelementsl The maximum external diameter of r the reamer is preferably someWhatsm-aller thanzthe diameter 'ofthe bonezW but is1substantially greaterithanfthe external-,diameter ofxthe drilli'pipe. f

lIn making use of `the invention, constructed as describedabove, themeamer is.,connected into a stringof drill piperinthe manner shownin'Figure 11, `so ,that the reamenwill vrotate .with1the string. During normahdrilling operations the reamer will merely rotate with the string and .circulation-oftdrilling duid in ,the well bore maytakeplace freely through the grooves ZZ'between theeuttingelements 16. When itisdesired toremove the:string, however, `should Vthe reamer enter akey-seat in the'bore inzwhich there would belikelihood thatY the drill c ollars might become stuck,.the endiportions of the cutterelements :16, where cutting portion of the reamer is lof smallest ,diameter will Ienter the key-seat rstqand the reamerimay be rotated with the string tocut away and enlargethe key-seat. Inithe event-.thatthe reamer should become wedged in-the key-seat, the reamer, beoausemfthe tapering conguration of the cutter elements may bereadilyl released 'by :the v,exertion of La `downward force on thestring. fMoreover, becauseof itheztapering shap e of the cutter elements due to the presence ofthe weld deposits 118 and 20, mudor other similar-material does not clog the grooves and interfere with free circulation ofuid past the reamer.

During the reaming operation ofthe tool-thereis .a tendency, due to the spiraled arrangement of theieutter elements, for the reamer to, move outof theakeyfseat, so that the reamer isprevente'd from vbecoming stuck in the key-seat as the reamer is movediinto thekeyeseat while being rotated.

Because of tapering shape yof the .reamer 4and. Vthe arrangement of its cutter elements thereamer of :the inventionmay also be used-by inserting the same in a well. casing'to cut away portionsl ofthe casing wherethe same may be bent, collapsed, or otherwise obstructed, and is'capable'of use under many different conditions to facilitate, the drilling and production of wells.

The invention thus provides a key-seat rearner which lisof usimple design `and rugged-construction and which may be economically manufactured.

It will be understood that the embodiment of the invention disclosed herein is intended by way of illustration only and that various changes can be made in the same within the spirit of the invention and the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimed as'new and rvdesired to secure by Letters Patentisa- 1. A key-seat reamer comprising a tubular body, means for connecting the'body at its opposite -ends-intoastring of drill pipe for-rotation with the string in a well bore, external, peripherally spaced, radially extending cutter elements on the body, each of said elements having a at surface positioned in tangential contact with the ex- -ternal 4surface of the body and an advancing side face forming a leading 'edge-and a trailingside 1face, weld deposits Valong-said facesl securing theelernents to 'the' body,th e weld deposit "along said advancing-#faces ter minating radially inwardlyj of Asaid yleading edges andlthe weld deposits along said I trailing 1faeesextending A radially substantially completely across the width otr-said trailing faces.

'2. A -key-seat-reamercomprising Vauti'iblularbo'dy having a substantiallyuniform external diameterithroughoutitsflengthfmeans `for connecting the body:atits-oppositefendsinto a string ofi-'drill pipe forv rotation withfthe stringY in a Y well f bore, external, peripherally-spaced,` Iradially-extendingA cutter-elements onithe body,-each of said elements having a'at -sur'face ipositioned in tangential cont-act with 4theexternalfsurface-'ofthe body and yan advancing side face 'forming -a leading edge which-slopes longitudinally ifroma location of :maximum externaldiameter mediate the -ends of ithetbody to a location-ot minimum external diameter adjacent an endof the body, radiali-yA outwardly tapering Y weld deposits alongA the 'f faces securingthe elements to thefbody, 'the -weld `deposits along kvsaid advancingfaces-:terminating4 radially inwardly of-said leading edges-and the welddepositsfalongsaid trailing faces extending radially substantiallyecompletely across the-width oflsaid trailingf faces.

References,,Citediinfthelelofi this ipatent UNITED STATES PATENTS 

